The present invention is directed to a process for the manufacture of pitch foams and to products resulting from this process. The invention includes the subsequent conversion of the pitch foams to carbon and graphite foams and to the products resulting therefrom.
It is known in the prior art that pitch foams can be prepared that have a variety of uses, such as, for example, as coatings, soil aerators, humidity regulators, and insulators in the building industry. Pitch foams can also be used for the manufacture of carbon or graphite foams. Bonzom et al, U.S. Pat. No. 4,276,246, issued Jun. 30, 1981, disclose the preparation of pitch foams in which pitch derived from a steam cracking residue, asphalt, or coal tar, or mixtures thereof, is expanded at elevated temperature in a mold by means of a porogenic agent.
Carbon and graphite foams have also been obtained by the carbonization of foams of plastic materials (thermoplastic or thermosetting), e.g., phenolic resins, or polyurethanes. Arnold et al, U.S. Pat. No. 4,832,881, issued May 23, 1989, disclose the preparation of a low density, open-celled microcellular carbon foam by the phase inversion of a polyacrylonitrile solution, followed by carbonization and, optionally, graphitization, of the foam.
I have discovered an improved process for the preparation of a pitch foam with a microcellular structure and a uniform pore size.
Accordingly, it is an object of the present invention to provide an improved process for the preparation of a pitch foam with a microcellular structure and a uniform pore size.
Other objects and advantages of the present invention will be apparent to those skilled in the art.